Magnetic separators



Oct. 10,1967 G.H.JONES f 3,346,116

MAGNETIC SEPARATOHS I N VEN TOR. G50/PGE' HENRY JNES Afro/wars.

' Oct. 10, 1967 G. H.JoNEs 3,346,115

MAGNETIC sBPARATQoRs Filed May 20, 1965 2 sheets-sheet 2 United States Patent O 3,346,116 MAGNETIC SEPARATORS George Henry Jones, Hayle, Cornwall, England, assignor to Quebec Smelting & Refining Limited (No Personal Liability), Montreal, Quebec, Canada, a body corporate of Canada Filed May 20, 1963, Ser. No. 281,529 Claims priority, application Great Britain, May 22, 1962, 19,562/ 62 1 Claim. (Cl. 210222) This invention relates to improvements in magnetic separators for separating magnetic particles of suitable size range from a -uid current from which they are to be separated, or from a mixture of magnetic and non-magnetic particles.

More particularly this invention relates to the constructions of the member or members which cause the separation of the magnetic particles from the non-magnetic particles and/or carrying fluid. These members which cause the separation may either be substantially flat plates as for example in the separator described in my British Patent No. 768,451. This separator operates with a fluid current feed consisting of solid particles in a stream of lfluid which is passed between grooved plates situated in a magnetic field. Magnetic particles in the feed are attracted to the grooved plates and after a predetermined period the feed is -cut off by closing a valve and a gentle stream of washing water is allowed to flow through the plates. The magnetic particles adhering to the grooved plates are washed clean, but left adhering to the plates. They may later be removed from the plates by scouring fluid after magnetic field has' been reduced to zero. The plates are arranged in parallel relation in a plate box, the individual plates having parallel triangular or other shaped grooves cut therein, to cause the necessary concentration of magnetic flux. In accordance with the present invention, a magnetic separator of this type is provided with a series of parallel plates arranged inthe box so as to leave narrow gaps between the plates for the passage of fluid containing magnetic Vand non-magnetic material. This box is located in a strong field created by electromagnets when the latter are energized. The invention is characterized in that each plate is made from .a non-magnetic compound in which there are embedded magnetizable particles, with the particles having been aligned in the direction of the magnetic field to `form a series of chains from one surface of the plate to the other du-ring its manufacture.

The non-magnetic compound may be either synthetic resin or rubber. The magnetizable particles may be in pow- 3,346,116 Patented Oct. 10, 1967 ICC y Referring to FIG. 1, which illustrates, somewhat diagrammatically, the separator of British Patent No. 768,451, the separator includes means supporting an electromagnet 11, the cores of which comprise like units 12 spaced apart to form the magnet poles. The windings 13 are illustrated on the cores 12.

The separator `further includes a table carrying a frame supporting an electric motor and gear box, or other driving unit, and two fluid control units 22, each carrying dependingly a separator unit 23. Each of the separator units is adapted, when the frame is in a respective position, to lie between the spaced apart core units 12 and to be lifted clear thereof when the frame is pivoted to another position.

Each fluid control unit is provided with a chamber, such as 25, therein and with ports, these ports being controlled by valves such as 26 and 27 operable by cams 29, 30 and 31 to admit, in suitably timed sequence, magnetic-particlecarryingiiuid, washing fluid and scouring fluid to the separator unit 23. The valves are operated by their respective cams to rocker arms 32, a tappet 33 being interposed between cam 29 and rocker arm 32 of valve 26. If desired, cam 29 may be arranged to close and open the electric circuit of the magnet at the same time as the valve 26 is opened and closed. Alternatively, a separate cam may be used for the magnet to allow for a correction of time lags of flux on switching a magnet coil. The cams 29, 30 and 31 are mounted -on a common cam shaft driven from the motor, and the valves are normally maintained in their closed positions by springs 14.

Magnetic-particle-carrying fluid is admitted to the unit from a source of supply by a flexible pipe line, and a return pipe line is provided for the return of su-rplus fluid to the supply source so that the fluid is maintained in constant circulation. An emergency overflow pipe is also provided.

Washing and sco-uring fluid is admitted to chamber 2S from a common supply source (not shown) to ilexible pip# ing (not shown), the fluid being admitted as washing fluid through a port controlled 'by valve 27 and as scouring fluid through a port controlled by a third valve (not shown). The washing fluid port may be smaller than the `scouring fluid port so that the washing fluid is admitted at a higher velocity, but in less volume, than the scouring fluid so that the washing fluid passes through the separator at a lower pressure than the scouring fluid. The initial velocity der form, in which case the powder may be eitherferroof typical embodiments thereof as illustrated in the accompanying drawings.

In the drawings: j I

FIGURE 1 is an enlarged diagrammatic sectional elevation of a detail of the separator shown in my British Patent No. 768,451;

FIGURE 2 is a sectional plan View of a plate box for use with a plate type magnetic separator, containing alternateiy flat and single sided plates;

FIGURE 3 is a sectional plan view of a plate box for use with a plate type magnetic separator, containing alternately flat andrdouble sided plates;

FIGURE 4 is a sectional plan view of a plate box for use with a plate type magnetic separator, containing llat plates separated by spacers; and

FIGURES 5 and 6 show part plan cross section views of yet further alternative types of plates.

of the fluid is received upon the valve faces and dissipated before reaching the magnet pole faces. The lift or movement of the washing fluid valve may be less than that of the scouring fluid valve.

Also mounted `on the cam shaft is another cam 142, adapted, through a tappet 43, and levers 144 and 144e, to apply pivotal tilting movement about a horizontal axis to a plate 45 disposed beneath a funnel 46 beneath separator unit 23. Tilting of the plate about a shaft 47 under the influence of cam 142 is so timed and arranged as to Vdirect successively the fluid from which magnetic particles have been separated, the washing fluid and the scouring uid into separate compartments 48, 49 and 50 of a trough 51 for collection and, if desired, re-treatment.

Each separator unit 23 includes a rectangular box-like member, open at the top and bottom, the walls 55 of which are of magnetic material and are, in the operative position, disposed closely adjacent the poles of the magnet cores 12. These Walls 55 are magnetized by the magnet 11 and themselves form the magnetic poles of the separator unit 23. The upper portions 56 of the walls V55 may be of non-magnetic material such as, for example, brass 4brazed or otherwise secured to Wal-ls 55 and secured to the control units 22. Interiorly of each separator unit are a plurality of plates 58 of magnetic material which may be spaced slightly apart by suitable means. These plates are arranged in the box having the Walls 55.

Referring now to FIGURES 2, 3 and 4, which show three different types of plate arrangements, inall cases the Iplate box 34 is adapted to t inside the separator illustrated in my aforesaid British Patent No. 768,451. The FIGURE 2 arrangement consists of a number of plates 38 having integral spacers 37 on one side and a single fiat plate 36. The arrangement of FIGURE 3 shows a construction in which flat plates 36 alternate with plates 40 having integral spacers 37 on both sides. Finally in the arrangement illustrated in FIGURE 4, flat plates 36 are :spaced apart by means of separate spacers 42. In all these three different arrangements of plates within the plate box 34, gaps 44 are left between the lplates, the fluid containing magnetic and non-magnetic materials passing down these gaps 44 between the plate arrangements. When a strong magnetic field is applied across the plate box 34, the magnetic material passing through the gaps 44 adheres to the plates until the magnetic field is reduced and the flow of scour water removes it.

Referring now to FIGS. 5 and 6, the plates consist of chains of magnetizable particles 74 which are embedded in a suitable non-magnetic compound 7. In a preferred form, particles 74 are in the form of a powder, for example ferro-silicon powder, and the non-magnetic compound is a synthetic resin compound, which is reinforced by means of strands of fiberglass 68 or other suitable reinforcing material. By magnetizable particles is meant particles which exhibit strong paramagnetic properties when placed in a magnetic field "but which do not retain any magnetism when the field is reduced to zero. The chains of powder Iparticles 74 are approximately parallel to one another and extend from one flat side of the plate to the other. The strands of fiberglass 68 extend in parallel relation to one another from the top to the bottom of the plate. In the preparation of such a plate, the ferro-silicon powder is mixed With a synthetic resin compound in fluid form, which is allowed to set in a strong magnetic field directed perpendicular to the surface of the plate. In this way, the particles of the ypowder tend to align themselves in chains in the direction of lines of force of the applied magnetic field. In FIG. 5, the particles are of small size and, consequently, it is possible to obtain quite a number of chains 74 between individual strands of fiberglass 68. On the other hand, where the particle size is larger, fewer chains are obtained between the strands, as shown in FIG. 6.

Instead of using a ferro-silicon powder to form the chains of particles, magnetite (Fe304) in powder form may be used, since it exhibits strong magnetic properties as does ferro-silicon powder. Instead of using synthetic resin as the non-magnetic compound, rubber may be used.

In operation, when the plates are arranged in any one of the plate boxes shown in FIGS. 1, 2 or 3, and the plate box itself is located in a magnetic separator such as illustrated in FIG. 1, the change of particles 74 of ferro-silicon powder or magnetite becomes strongly magnetic due to the magnetic field set up between the pole pieces on either side of the plate box, and hence cause the magnetic par-v ticles from a fluid stream passing through the plate box to adhere to the plates during the feed and wash periods. When the magnetic field is reduced to zero during the scour period, the magnetic particles, which have been washed clean, are removed from the plates, since the change of magnetic particles do not-retain any magnetism once the main field has been switched off.

It has been found that, due to the presence of the chains of magnetizable particles, espectially ferro-silicon powder particles or magnetite particles, the efficiency of the separator is slightly higher than that of the conventional magnetic separator.

While specific embodiments of the invention have been shown and described in detail to illustrate the application of the principles of the invention, it will be understood that the invention maybe embodied otherwi-se without departing from such principles.

What I claim and desire to secure by Letters Patent is:

A magnetic separator comprising, in combination, a box; plural plates arranged in closely spaced parallel relation in said box to define narrow gaps between adjacent plates, each plate being formed of a non-magnetic compound; magnetizable particles imbedded within each plate; a pair of electro-magnet means arranged on opposite sides of said box; means for energizing said electro-magnetic means to create a strong magnetic field in a direction substantially perpendicular to the surfaces of said plates; inlet means for admitting fluid, containing magnetic and non-magnetic particles, into said box to flow through said gaps; outlet means for discharging the fluid from said box after the magnetic particles have been separated therefrom; said magnetizable particles being aligned in the direction of the magnetic field to form a series of chains of particles extending from one surface of each plate to the other surface of each plate; and strands of fiberglass embedded in each plate to reinforce the same.

References Cited 11/ 1943 Great Britain. 6/ 1958 Great Britain.

REUBEN FRIEDMAN, Primary Examiner.-

F` W. MEDLEY, Assistant Examiner. 

